1. Field of the Invention--The present invention relates generally to the art of filling flexible containers or bags with sterile fluids, and more particularly to a system for automatically filling intravenous (IV) solution bags at a high rate of speed in a sterile, aseptic manner without requiring a clean room or other sterile environment or extensive sterilizing of equipment.
2. Description of the Related Art--The presence of particulates and viable organisms must be kept within specified limits when filling flexible containers.
Depending on the solution, filling with very low levels of viable contamination may be allowed when sterility is thereafter achieved by a subsequent sterilizing process. Alternatively, the solution may be produced sterile and transferred into the flexible container by an aseptic filling process which maintains sterility by excluding viables.
In prior practice, flexible containers were filled in a clean room under a hood capable of maintaining sanitary conditions within specified limits. For aseptic filling, bags would initially be sterilized internally and at least partially externally and kept at a very low level of contamination during the filling process. It was essential that a high degree of care be maintained throughout all phases of a controlled or aseptic filling process. IV bags were subsequently sterilized after filling to ensure the required sterility even if originally filled by highly controlled methods.
Methods and machines are currently used in related areas of the art to minimize human labor (and therefore the threat of contamination) and to utilize automated processes where possible. These methods and machines, however, have certain significant shortcomings. Many machines are not able to use preformed bags or containers. Filling IV bags in these machines is an integral part of manufacturing the bags. See, for example, U.S. Pat. Nos. 3,269,079 issued on Aug. 30, 1966 to Schmied for "Method of and Apparatus for Sterile Packaging of Sterile Consumer Goods"; 3,376,687 issued on Apr. 9, 1968 to Gewecke for "Method of Preparing a Packaged Parenteral Solution"; 3,466,841 issued on Sept. 16, 1969 to Rausing for "Method of Packaging Sterile Filling Material Under Aseptic Conditions"; 3,538 669 issued on Nov. 10, 1970 to Broman et al. for "Method of Preparing a Packaged Sterile Solution"; 4,045 939 issued on Sept. 6, 1977 to Baumstingl for "Process for the Production of a Packaging Receiving a Sterile Liquid"; and a 4,417,607 issued on Nov. 29, 1983 to Scholle et al. for "Apparatus and Method for Aseptically Filling Flexible Containers." It is impossible to separate the filling and bag production aspects of these processes.
Additionally, many machines designed to fill preformed bags utilize bags that require a cap member to be attached after the filling process. The presence of these caps demands the use of an additional, complex mechanism for removing and replacing the caps. The filling equipment usually must also include a threaded adapter means to accomplish an airtight seal for filling. See, for example, U.S. Pat. Nos. 4,530,202 issued on July 23, 1985 to Powell et al. for "Container Filling Machine and Method"; and 4,452,030 issued on June 5, 1984 to Inada for "Contamination-free Method and Apparatus for Filling Spouted Bags With a Fluid."
Several systems require the entire bag or container to be completely sterilized (i.e., internally and externally) as well as sterile conditions in the filling chamber of the machine during each cycle of the filling process. This requires a large quantity of sterilizing agent and, in cases of large scale production, considerably slows the production of filled bags or containers. See, for example, U.S. Pat. No. 3,486,295 issued on Dec. 30, 1969 to Rausing et al. for "Method of Packaging Sterile Liquids."
Several patents recite and disclose the steps common to most any bag filling system. See, for example, U.S. Pat. Nos. 2,949,712 issued on Aug. 23, 1960 to Bieberdorf et al. for "Liquid Packaging Method"; 3,403,064 issued on Sept. 24, 1968 to Bellamy for "Method of Forming a Composite Plastic Container With an Inner and Outer Seal"; 3,514,919 issued on June 2, 1970 to Ashton et al. for "Packaging Fluids"; and 3,531,908 issued on Oct. 6, 1970 to Rausing et al. for "Method of Sterilizing and In Aseptic Conditions Filling a Flexible Container With a Sterile Liquid." These patents do not disclose any specific or efficient means for implementing the steps of the filling process. They therefore provide minimal guidance to one who wishes to incorporate the principals in an efficient production system.
The devices described above also are labor intensive and do not use automated processes to the fullest extent possible. Human labor has typically been required at one or more points in the process, thus increasing the risk of contamination and the precautions needed to insure safe processing. In U.S. Pat. No. 3,491,503 issued Jan. 27, 1970 to Ashton, et al. for "Methods and Apparatus for Filling Presterilized Containers," means are disclosed for aseptically filling a preformed bag. The second filling tube is inserted into the machine and is clamped. The outer end of the fill tube is then opened and sterilized. A pressure differential is used to keep the tube opened. Once the tube's outer end is sterilized, the clamp is removed, the bag is filled through the tube and finally, the tube is again sealed using heat sealing. The device employs several manually operated controls.
In U.S. Pat. No. 4,494,363 issued Jan. 22, 1985 to Rica, et al. for "Method and Apparatus for Aseptically Filling Containers," a machine for filling preformed bags is disclosed. A bag is secured to the machine and a vacuum head removes a lid covering a tubular fitment from the bag. The engaged fitment, the entire fill chamber, the lid, the lid removing means and the fill tube of the machine are all sterilized. Then the fill tube lowers, engages the bag fitment and fills the bag. Thereafter, the lid is heat sealed onto the end of the fitment and the bag is removed.